Composition for cleaning hard surfaces



United States Patent 3,186,947 COMPOSITION FOR CLEANING HARD SURFACESLouis McDonald, Altadena, Caiif., assignor to Kelite Corporation, LosAngeles, Calif., a corporation of California No Drawing. Filed June 16,1958, Ser. No. 742,006 2 Claims. (Cl. 252137) This invention relates tothe cleaning art and has particular reference to a novel composition andmethod for cleaning hard surfaces.

The removal of soil from hard surfaces, particularly those hard surfaceswhich are sensitive to chemical attack, has usually been accomplished bythe use of moderately alkaline cleaners embodying agents which inhibitcorrosive attack upon the metal surface. For example, compositions madein accordance with US. Patent No. 2,381,124 have been successfullyemployed in cleaning aluminum surfaces without deleterious corrosiveattack upon the surface. Such a composition is also successfully usedfor cleaning bare ferrous metals without corrosive attack or promotingrusting after cleaning.

In the cleaning of hard surfaces which are coated with protective anddecorative organic finishes, it is frequently found that mildly alkalinecleaners, even those inhibited against attack on light metal alloys suchas aluminum, will cause the finish to streak, bring about loss of glossand accelerate the deterioration of the organic finish. The cleaning ofsuch surfaces with solutions essentially comprised of organic non-soapdetergents, such as alkyl aryl sulphonates, and employed as essentiallyneutral pHs in the region of 7-8, will also cause streaking of certainorganic finishes with accompanying spotting, formation of blemishes andaccelerated deterioration. Frequently, too, if the solution of organicnon-soap detergent is employed at sufiicient concentration to removeoily soils, it will also remove protective waxes. This difiiculty isalso inherent in the use of mildly alkaline cleaners, even corrosioninhibited cleaners. The problem of cleaning light alloys and hardsurfaces finished with protective and decorative organic finishes isprevalent in the washing of vehicles such as automobiles, buses, trucks,airplanes and various and other common articles of commerce which areeither fabricated of aluminum and/or which are painted with decorativeand protective organic finishes. In the industrial areas of cleaningairplanes and vehicles, such as motor vehicles and buses, a real problemexists. These vehicles are usually polished with wax polishes and theyare severely soiled with oily soils, solid dirt from atmospheric falloutand additionally the organic surface or the light alloy surface isfrequently oxidized from weathering. To properly clean the surface it isdesirable to remove the oily soil and solid dirt and at the same time toreduce or remove the oxide surface. Frequently it is desirable toaccomplish this without dewaxing the surface.

This same type of problem is prevalent on a somewhat larger scale in thecleaning of railroad equipment such as railroad passenger cars. Here thepractice has been to use rather strongly acid cleaners embodying suchagents as sodium bisulphate and employing a cleaning bath operating atlevels of pH in the range of 2 and 3. This type of cleaner effectivelyremoves oxidized paint. However, it is not suitable for use on fineorganic finishes and for use in conjunction with vehicle components madeof aluminum and similar light alloys.

One of the principal objects of the present invention is to provide anovel cleaning composition which is not subject to the above and otherdisadvantages of the prior art cleaners.

More specifically, it is an object of the present invention to providecleaning compositions adapted to remove soil, and to reduce oxidizedfinish, from hard surfaces such as aluminum alloys and organic surfaceswithout corrosive attack, streaking, spotting, dewaxing or otherdeterioration of the surface being cleaned.

Other objects and advantages of the present invention it is believedwill be readily apparent from the following detailed description ofpreferred embodiments thereof.

Briefly, this invention comprehends within its scope the discovery thatcompositions embodying a major proportion of ammonium sulphate, which isessentially neutral in terms of pH when dissolved in water inconjunction with certain organic detergents and rinse assistants, willsatisfactorily accomplish the desired cleaning of hard surfaces withoutdeleterious elfect. The ammonium sulphate appears to function as acomplexing agent in a dual capacity. First, it complexes metallic oxidesto bring metal ions into solution and to hold them complexed andunreactive. Secondly, the complexing agent serves to promote micelleformation of the organic detergent involved to accomplish effectiveremoval of oily soils and solid dirts without attack on temporaryprotective finishes such as wax or the organic protective or decorativefinish or without attack on the aluminum alloy. Any organic nonsoapdetergent of the anionic, cationic or nonionic type can be employed as aminor constituent of the composition. Such organic non-soap detergentsare well known in the art and are disclosed in many references such as,for example, Sisley et al., Encyclopedia of Surface Active Agents(Chemical Publishing Co.) and Swartz et 211., Surface Active Agents(McGraw-Hill). It has been found, however, that specific combinations oflong chain anionics of the class of alkyl aryl sodium sulphonate andshort chain molecules of the same species are highly effective in thepresence of ammonium sulphate in the removal of the specific soilsWithout causing deleterious attack or streaking on the organic finish.

Specifically, alkyl aryl sulphonates having molecular weights of theorder of the molecular weight of dodecyl benzene sodium sulphonate andanother, lower, alkyl aryl sulphonate having a molecular weight of theorder of the molecular weight of naphthalene diisobutyl sodiumsulphonate when used in substantially equal weight proportions as minorconstituents, with ammonium sulphate as the major constituent, exhibitthe optimum cleaning behavior described above. These lower alkyl arylsulphonates fall into two general classes having generic formulae asfollows:

wherein R is an aromatic ring, X is a member of the group consisting ofsulphonic acid and salts thereof, r is an aliphatic group having no morethan 5 carbon atoms and n is an integer not more than 2, and r isselected from the group consisting of hydrogen, methyl, and ethyl.Diisobutyl methylnaphthalene sodium sulphonate is a typical example ofthis class. Other are di-isopropyl naphthalene sodium sulphonate anddiisobutyl naphthalene sodium sulphonate.

wherein R is a naphthalene ring, X is a member of the group consistingof sulphonic acid and salts thereof, and y is an integer from 1 to 6.Compounds within this class are polymeric naphthalene methylenesulphonates. Typical of this class is polymeric naphthalene tetramethylene sodium sulphonate which is formed by sulphonating naphthalenewith a strong sulphonating acid, diluting with water and addingmethylene groups by reaction with formaldehyde. Then formaldehyde in thepresence of free sulphuric acid initiates polymerization.

It has been further discovered that the formation of water spots, whichnormally form on rinsing of a detergent bath from the surface cleanedcan be eliminated by the inclusion of certain complex molecularlydehydrated phosphates in minor amounts.

Materials which show strong ability to complexi.e., to form two or morecompounds or ions or to form complex groups are foundin the generalclasses of chemical compounds known as the cyanides, ammonia, ammonium,oxonium and similar compounds. It is well known, for example, thatsimple cyanides will combine to form complex cyanides embodying mixedcations. Similarly, ammonia and ammonium compounds form well knowncomplexes such as nickel ammonium sulphate or cuprous ammonium nitrate.Phosphonium and sulphonium compounds constitute lesser known examples.These materials fall under the general class of compounds that formWerner complexes. Among the most satisfactory for this purpose is thecommon material ammonium sulphate, and it is believed that this compoundfunctions in the manner of a Werner complex when used in accordance withthis invention. Other ammonium compounds, such as diammonium phosphateor ammonium nitrate could be used but are less desirable for reasons ofcost or possible hazard.

It has been discovered in substance that the replacement of alkalinecleaning assistants such as sodium silicate, trisodium phosphate,tetrasodium pyrophosphate or sodium carbonate by ammonium sulphateeliminates the attack on light alloy or hard surfaces finished withorganic protective and decorative finishes. Similarly, by the embodimentof ammonium sulphate in compositions consisting of organic detergentssuch as an alkyl aryl sulphate, the cleaning efficiency is improved andthe deleterious action of the organic detergent on organic finishes iseliminated. I

The compositions are utilized by dissolving in water to form aqueoussolutions of concentrations in the neighborhood of /22 oz./gallon. Thesolutions are applied manually with a sponge or mop or brush onto thesurfaces to be cleaned. After application the solution and soil isflushed olf with a running cold water rinse. It is not necessary tomanually wipe the surfaces dry. They will dry by draining andevaporation to leave a bright, unblemished surface.

It is also possible to apply the cleaning solution by spray using theimpingement force of the spray to assist in the removal of the soil.Following the spray application the detergent solution and soil areremoved by a pressure cold water rinse.

Another method is to clean small parts by immersion in a bath of thedetergent solution followed by immersion rinse or spray rinse in theconventional manner.

For reasons of economy and convenience of handling and shipping thecompositions are best made as dry powders. It is also possible tocommercially furnish such a composition in the form of an aqueoussolution or concentrate without departing from the scope or spirit ofthis invention.

The following specific examples illustrate the compositions and processof the present invention, but it is to be understood that the inventionis not to be specifically limited thereto: a

Example 1 Weight percent Ammonium sulphate 82 Diisobutyl naphthalenesodium sulphonate 7' Dodecyl benezene sodium sulphonate 8 Sodiumtripolyphosphate 3 The composition of Example 1 produces an aqueouscleaning solution which is exceptionally free rinsing, is eificient inthe removal of oily solids and solid dirt, and leaves both metallic andpainted surfaces with a high gloss.

The diisobutyl naphthalene sodium sulphonate functions as an anti-cakingagent in addition to furnishing a strong wetting component which causesthe foamto break rapidly, disperses the solid dirt and influences therapid rinsing characteristics of the composition.

It is possible to utilize a composition similar to the above without theinclusion of a complex molecularly dehydrated phosphate such as sodiumtripolyphosphate, sodium tetraphosphate, sodium pentametaphosphate orsodium hexametaphosphate. It is found, however, that theembodiment ofminor amounts of these complex phosphates improve rinsability andeliminate deposition of water spots from hard water salts. The use ofcomplex phosphates such as tetrasodium pyrophosphate or orthophosphatessuch as trisodium phosphate is not feasible due to the increase inalkalinity and pH that they contribute to the cleaning bath. However,primary and secondary orthophosphates such as monosodium phosphate ormono and diammonium phosphates could be desirably employed.

The cleaner baths of the present invention operate satisfactorilywithout deleterious effect on aluminum alloys or organic finishes overthe range of pH of 4.2-7.6.

Very simple, but satisfactory anionic detergent-containing compositionswithin the scope of the present invention are as follows:

Example 2 Weight percent Dodecyl benzene sodium sulphonate 1O Ammoniumsulphate Example 3 Diisobutyl naphthalene sodium sulphonate 1O Ammoniumsulphate 90 The following example illustrates the use of a cationicdetergent:

The Triton detergent of the above Example 5 was an alkyl phenol ethyleneoxide condensate having 3-7 ethanoxy groups.

The proportions of the compositions of the invention may be variedwithin rather wide limits. Preferred proportion ranges are as follows:

Weight percent Ammonium sulphate 4097 Non-soap organic detergent 3-60Phosphate 0-5 Having fully described my invention, it is to beunderstood that I do not wish to be limited to the details set forth,but my invention is of the full scope of the appended claims.

I claim:

1. A cleaning composition for hard surfaces consisting essentially of 40to 97 percent by weight of ammonium sulphate and 3 to 60 percent byweight of an organic detergent mixture comprising approximately equalproportions by weight of diisobutyl naphthalene sodium sulphonate anddodecyl benzene sodium sulphonate.

2. The composition of' claim it, wherein the composition includes aminor proportion of sodium tripolyphosphate.

(Other references on following page) $4 My, Q

References Cited by the Examiner UNITED STATES PATENTS Englund 252--137Daimler 252-161 Zizinia et a1 252--161 Flatt 252161 131113 et a1 252-161Olin 252152 Butler 252-161 Bloch 252-161 Sylvester 252-137 Ricciardi252161 Stewart 252--138 Vitale 252-135 ALBERT T. MEYERS, PrimaryExaminer.

JULIUS GREENVVALD, Examiner.

1. A CLEANING COMPOSITION FOR HARD SURFACES CONSISTING ESSENTIALLY OF 40TO 97 PERCENT BY WEIGHT OF AMMONIUM SULPHATE AND 3 TO 60 PERCENT BYWEIGHT OF AN ORGANIC DETERGENT MIXTURE COMPRISING APPORXIMATELY EQUALPROPORTIONS BY WEIGHT OF DIISOBUTYL NAPHTHALENE SODIUM SULPHONATE ANDDODECYL BENZENE SODIUM SULPHONATE.
 2. THE COMPOSITION OF CLAIM 1,WHEREIN THE COMPOSITION INCLUDES A MINOR PROPORTION OF SODIUMTRIPOLYPHOSPHATE.